The present invention is drawn toward plasma electromagnetic waveguides and plasma electromagnetic coaxial waveguides that are reconfigurable, durable, stealth compatible, and flexible.
A waveguide is generally configured such that current and voltage distributions can be represented by one or more traveling waves, usually in the same direction. In other words, the traveling wave patterns in current and voltage are generally uniform.
A waveguide can be likened unto a coaxial line having the central conductor removed. These waveguides, despite the absence of the central conductor, are still capable of carrying higher frequency electromagnetic waves. Therefore, an important use of waveguides in general is for the transmission of high frequency power, e.g., coupling a high-frequency oscillator to an antenna. Although high frequencies may be transmitted along coaxial cable, a waveguide is generally better than coaxial lines for transmitting large amounts of high frequency signal. If the goal is to transmit lower frequency electromagnetic waves, coaxial lines are generally better. However, only a maximum amount of power may be transmitted along a coaxial line due to the breakdown of the insulation (solid or gas) between the conductors. Additionally, energy is often lost in the insulating material that supports the center conductor.
Whether dealing with metal waveguides or metal coaxial lines, there are serious limitations as to what frequency of waves may be propagated. This is in part due to the material that has been traditionally used to in the construction of waveguides. For example, since metal has fixed properties, a metal waveguide is only capable of propagating very specific signals. This is likewise true to some extent with coaxial cables or lines.
Gas has been used as an alternative conductor to metal in various applications. In fact, in U.S. Pat. No. 5,594,456, a gas filled tube coupled to a voltage source for developing an electrically conductive path along a length of the tube is disclosed. The path that is created corresponds to a resonant wavelength multiple of a predetermined radio frequency. Though the emphasis of that patent is to transmit short pulse signal without trailing residual signal, the formation of a conductive path between electrodes in a gas medium could be relevant to other applications.
As such, it would be useful to provide plasma waveguides and plasma coaxial waveguides that are capable of propagating electromagnetic waves in a desired direction or along a desired path. Not only would these waveguides and coaxial waveguides be reconfigurable with respect to the range of signal that could be propagated, but these waveguides could also be designed to be more stealth, durable, and flexible than traditional metal waveguides and coaxial lines.
It is an object of the invention to provide plasma waveguides and plasma coaxial waveguides that are reconfigurable with respect to the breadth of electromagnetic waves that may be directionally propagated along a given path without changing the geometry of the enclosure.
It is another object of the invention to provide plasma waveguides and plasma coaxial waveguides that are more stealth, flexible, and/or durable than traditional waveguides.
These and other objects may be accomplished by the plasma waveguides and plasma coaxial waveguides of the present invention.
Specifically, the present invention discloses and describes an electromagnetic waveguide comprised of a) an elongated non-conductive enclosure defining a propagation path for directional electromagnetic wave propagation; b) a composition contained within the enclosure capable of forming a plasma, said plasma having a skin depth along a surface within the enclosure such that the electromagnetic waves penetrate the skin depth and are primarily propagated directionally along the path; and c) an energy source to form the plasma. Optionally, an energy modifying medium to reconfigure the waveguide such that electromagnetic waves of various wavelengths may be propagated directionally along the path may be used.
Additionally, a reconfigurable coaxial electromagnetic waveguide is disclosed which is comprised of a) a first elongated non-conductive enclosure defining a propagation path for directional electromagnetic wave propagation, said first enclosure further comprising a first open end and a second open end, said first open end and said second open end being connected by a channel, said channel being oriented along the direction of wave propagation; b) a second elongated non-conductive enclosure positioned within the channel of the first enclosure; c) a first composition contained within the first enclosure capable of forming a first plasma, said first plasma having a skin depth along a surface of the first enclosure; d) a second composition contained within the second enclosure capable of forming a second plasma, said second plasma having a skin depth along a surface of the second enclosure such that the electromagnetic waves penetrate the skin depth within the first enclosure and second enclosure and are primarily propagated directionally along the path; and e) at least one energy source to form the respective first and second plasmas. Optionally, an energy modifying medium to reconfigure the waveguide such that electromagnetic waves of various wavelengths may be propagated directionally along the path may be used.